You have a book in your Kindle application (in your iPhone). You want to completely remove it.
1. Press and hold the book title and remove the book from your device (e.g. your iPhone).
2. Login your Amazon account.
3. Search for the Manage Your Content and Devices link.
4. Go to Manage Your Content and Devices.
5. Select Books or Docs beside the Show label.
6. Select the book and click Delete button.
7. On your device (e.g. your iPhone) scroll down to refresh your Kindle books.